Term
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Definition
| the breakdown of organic matter; the transformation of chemical compounds into simple elements |
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Term
| why is decomposition important? |
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Definition
| small but critical step in global carbon cycle, soil fertility, soil structure and carbon storage. |
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Term
| what are the biological drivers of decomposition? |
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Definition
microbe-driven process
-extracellular enzymes
-hydrolysis
-oxidation
-OM-derived carbon lost as CO2 during respiration
-dead microbial cells also accumulate in decaying OM ("necromass") |
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Term
| what role do insects play in decomposition? |
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Definition
direct impacts:
fragmentation of organic matter,
passive or active transport of organic matter into soil profile,
carbon and nutrients lost to solution or to atmosphere via respiration or metabolic processes
indirect impacts:
animal wste stimulates or "primes" microbial decay of existing organic matter
stimulates/suppresses microbial activity
exploiting soil microbes:
exosymbionts - some insects bring their own decomposed microbe community along with them.
endosymbionts - inside insects. most insects. many can degrade complex substrates including cellulose and ligning |
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Term
| how do ants decompose organic matter? |
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Definition
wood ants form large nests on forest floor. they are generalist omnivores; fragment detritus, concentrate organic matter and distribute at depth, facilitate microbial decay.
they significantly impact carbon and nutrient dynamics within nest and surrounding soil.
fungal cultivation practiced in over 80 ant species. |
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Term
| how do termites decompose organic matter? |
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Definition
diet range of various termite species:
wood and grass feeders feed directly on wood and grass tissue,
litter feeders range of feeding habits including dead wood, grass, leaf litter, fungus comb and conidia.
soil-wood feeders feed on decayed wood at interface with soil
soil feeders ingest mineral soil to access organic matter therein
organic matter import and fragmentation. selective, but enhanced microbial degradation. significant mineralization of carbon and nutrients. |
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Term
| how do termites digest this material? |
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Definition
extracorporeal digestion
differs from others in that fungal structures are not ingested. instead fungi-degraded organic matter is consumed. fungal combs constructed from saliva, macerated organic matter, and fungal hyphae. fungi degrade organic matter which is then consumed by termites.
symbiont-aided digestion. |
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Term
| why is carrion a unique input to the soil? |
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Definition
carrion refers to dead/decaying animal carcasses
carrion decomposition is unique:
primarily a soil surface process
diverse organic matter imported to carrion
export products have large fingerprint on decay in surrounding soil |
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Term
| what kinds of insects specialize on carrion decomposition? |
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Definition
primarily flies and beetles that contribute directly to carrion decay
flies: blow fly and flesh fly -> larvae contribute to carrion decay |
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Term
| how do dung beetles impact decomposition? |
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Definition
tunnelers: burrow deep champers below dung
dwellers: live within or just below dung
rollers: form dung balls and roll away from dung to create subsurface chamber
modify spatial distribution of organic matter
increase rates of carbon and nitrogen input to bulk soil
suppressed CH4 emission, likely due to increased soil aerification
in all cases, dung serves as provision for larvae |
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Term
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Definition
piophila casei
the cheese is produced in an ingenious and original manner, ie during the course of development of the cheese fly and usually within rural households in low hygienic conditions, from the aspects of both production and storage.
wikipedia: Casu marzu is created by leaving whole Pecorino cheeses outside with part of the rind removed to allow the eggs of the cheese fly Piophila casei to be laid in the cheese. A female P. casei can lay more than five hundred eggs at one time.[2][4] The eggs hatch and the larvae begin to eat through the cheese.[5] The acid from the maggots' digestive system breaks down the cheese's fats,[5] making the texture of the cheese very soft; by the time it is ready for consumption, a typical casu marzu will contain thousands of these maggots |
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